Today, environmental-friendly material (e.g., plastics, metals, etc.) treatment technologies are under development. And, a portable UV treatment (i.e., UV curing, drying, coating, and printing) apparatus enabling free movement and worker's own carrying when coating, drying, and printing curved surfaces of building accessory materials (a bathtub, a marble bottom and wall body, etc.), industrial materials (e.g., car plastic parts, car exterior cladding frames), etc. capable of meeting the above consumer's demand is under development and deployment as the recent consumer's demand changes to environmental-friendly materials occupying a small installation space and also capable of providing material treatment (curing, drying, coating, printing, etc.) enabling easy movement and worker's own carrying.
For specific local or curved part surfaces of the above products, materials need the curing, coating, drying, and printing apparatus. In detail, the apparatus irradiates UV into a coated or printed product with the listed materials using a cylinder type oval condenser mirror making use of a high pressure mercury or metal long-arc lamp that is a high pressure UV lamp or a metal and mercury lamp, and irradiates UV (particularly, ‘i’ rays of 365 nm) at an illumination necessary for UV photo reaction and executes operations such as UV curing, drying, printing, and coating. Generally, a conventional apparatus using a long-arc lamp is of a fixed type, and another kind is a spot curing apparatus using a short-arc lamp for irradiating UV and curing an area of 3 to 10 mm.
However, in the above conventional fixed and portable UV curing apparatus using the long-arc lamp, a cooling structure is of a type in which a fan (i.e., a cooling unit) is installed in a right-angled direction or vertical direction of the long-arc lamp. Because of this, a high pressure long-arc lamp has a short lifetime and consumes a high replacement cost. Also, in case of a high pressure metal UV lamp or a high pressure mercury lamp, as cooling non-uniformity occurs, substances within a high pressure UV lamp (i.e., mercury, and metals for UV radiation) can suffer abnormal convection and thus, can deteriorate the quality of UV curing, drying, coating, and printing. In case of a spot curing UV apparatus using a short-arc lamp, movement is difficult and a fixed type is used. The spot curing UV apparatus is used for a very small area below 10π.
Accordingly, in recent years, a curing work using a long-arc UV lamp is becoming a new alternative.
The present invention presents a UV curing system using the long-arc UV lamp that can be hand carried by a worker.
The UV curing, printing, drying, and coating refers to a scheme of inducing a chemical UV reaction dependent on the addition of a kind of synthetic resin and hardening a product surface. In case of a curing reaction, a chemical component of resin is transformed from monomer to polymer, and a micro hand carry type curing unit is mainly used for the car exterior coating curing and surface curing treatment for a building interior bottom or tile, a bathtub, a marble, etc.
Conventional ink and coating (with water or solvent base) is dried through an evaporation process (i.e., heat curing and heat drying) for eliminating about 40% of a capacity of a coated ink. The UV curing ink and coating includes a photoinitiator that is a special composition sensitive to UV radiation rays. An exposure to UV radiation rays causes a polymer net knot in which ink is crosslinked beginning a rapid reaction, and is transformed from liquid to solidification state. A UV curing (drying, coating, and printing) process is a chemical reaction called a ‘photopolymerization’, and is a technology of changing monomer into polymer by UV light. UV curing materials are generally composed of monomer, oligomer (prepolymer), photoinitiator, and other additives. If irradiated by UV light, the photoinitiator is excited and, by this excitation energy, monomer (liquid) converts into polymer (solid). This process does not need a solvent. Products are not dried by heat but are cured by UV light. Thus, an energy loss is very small compared to heat drying and heat curing. For this reason, a contribution to the recent green (environmental-friendly production and manufacturing process) energy field is very large.
It is basically different from heat drying, i.e., a method of gasifying a solvent by heat energy and solidifying the solvent.
The prior art provides a substantial matter of a UV curing apparatus including a UV lamp, a reflection mirror surrounding the UV lamp, a lamp unit composed of a lamp house embedding the lamp and the reflection mirror, a rotary shaft installed in the lamp unit, a lamp installation mount embedding the lamp unit, and a handle installed in an end of the rotary shaft, wherein a shaft support means for supporting both-side ends of the rotary shaft is installed in the lamp installation mount, and the rotary shaft is fixed to a side wall of a lamp house to which the UV lamp of the lamp unit is fixed and in addition, is extended outside the shaft support means of the lamp installation mount and on the other hand, a rotation locking unit installed to press and fix the other end of the rotary shaft extending and protruding outside is provided in an outer wall of the lamp installation mount in which the shaft support means is installed.
However, the above prior art needs a cooling means for cooling a UV lamp gradually increasing in temperature during a long-time use process. But, the prior art does not disclose this cooling means and thus, can cause a disadvantage of disabling a long time use of a curing apparatus and UV irradiation non-uniformity resulting from cooling non-uniformity. For products presented from this technology, the currently developed curing equipment provides high efficiency in a cooling flow design compared to the prior art, and can make cooling constant for a length direction of a long-arc lamp because it is of a structure optimizing a cooling flow rate.